v.gu

fuenfteabgabe.c

@@ -0,0 +1,150 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <math.h>
+typedef struct {
+	int N;
+	double d;
+	double h;
+	double xmin, xmax, tmin, tmax;
+	double j;
+	double n;
+	int jmax;
+	int nmax;
+
+} soli_param;
+double *u0;
+double *uj1;
+void ustart(soli_param *sp) {
+	double N = sp->N;
+	double jmax = sp->jmax;
+	double h = sp->h;
+	double x = sp->xmin;
+
+	for (int j = 0; j <= jmax; j++) {
+
+		u0[j] = -N * (N + 1) / (pow(cosh(x), 2));
+		x = x + h;
+		printf("%f\n", u0[j]);
+
+	}
+
+}
+void ujeins(soli_param *sp) {
+	double jmax = sp->jmax;
+	double d = sp->n;
+	double h = sp->h;
+	for (int j = 0; j <= jmax; j++) {
+		if (j == 1) {
+			uj1[j] = (d * 6 * u0[j] * (u0[j + 1] - u0[j - 1]) / (2 * h))
+					- (d * (u0[j + 2] + 2 * u0[j - 1]) / (2 * pow(h, 3)))
+					+ u0[j];
+
+		} else if (j == 0) {
+			uj1[j] = (d * 6 * u0[j] * (u0[j + 1] - u0[j - 1]) / (2 * h))
+					- (d * (u0[j + 2]) / (2 * pow(h, 3))) + u0[j];
+
+		} else if (j == jmax - 1) {
+			uj1[j] = (d * 6 * u0[j] * (u0[j + 1] - u0[j - 1]) / (2 * h))
+					- (d * (2 * u0[j - 1] - u0[j - 2]) / (2 * pow(h, 3)))
+					+ u0[j];
+
+		} else if (j == jmax) {
+			uj1[j] = (d * 6 * u0[j] * (-u0[j - 1]) / (2 * h))
+					- (d * (2 * u0[j - 1] - u0[j - 2]) / (2 * pow(h, 3)))
+					+ u0[j];
+		} else {
+			uj1[j] = (d * 6 * u0[j] * (u0[j + 1] - u0[j - 1]) / (2 * h))
+					- (d * (u0[j + 2] + 2 * u0[j - 1] - u0[j - 2])
+							/ (2 * pow(h, 3))) + u0[j];
+		}
+
+	}
+
+}
+void nextu(soli_param *sp) {
+	int jmax = sp->jmax;
+	int nmax = sp->nmax;
+	double d = sp->d;
+	double h = sp->h;
+	double * unm = u0;
+	double * un = uj1;
+	double unp[jmax];
+	for (int n = 0; n <= nmax; n++) {
+		for (int j = 0; j <= jmax; j++) {
+			if (j == 1) {
+				unp[j] = 2*d*(
+								(un[j + 1] + un[j] + un[j - 1])
+										* (un[j + 1] - un[j - 1]) / h
+										- (un[j + 2] - 2 * un[j + 1]
+												+ 2 * un[j - 1])
+												/ (2 * pow(h, 3))) + unm[j];
+
+			} else if (j == 0) {
+				unp[j] = 2
+						* d*(
+								(un[j + 1] + un[j]) * (un[j + 1]) / h
+										- (un[j + 2] - 2 * un[j + 1])
+												/ (2 * pow(h, 3))) + unm[j];
+
+			} else if (j == jmax - 1) {
+				unp[j] = 2
+						* d*(
+								(un[j + 1] + un[j] + un[j - 1])
+										* (un[j + 1] - un[j - 1]) / h
+										- (-2 * un[j + 1] + 2 * un[j - 1]
+												- un[j - 2]) / (2 * pow(h, 3)))
+						+ unm[j];
+
+			} else if (j == jmax) {
+				unp[j] = 2
+						* d*(
+								(un[j] + un[j - 1]) * (-un[j - 1]) / h
+										- (2 * un[j - 1] - un[j - 2])
+												/ (2 * pow(h, 3))) + unm[j];
+
+			} else {
+				unp[j] = 2
+						* d*(
+								(un[j + 1] + un[j] + un[j - 1])
+										* (un[j + 1] - un[j - 1]) / h
+										- (un[j + 2] - 2 * un[j + 1]
+												+ 2 * un[j - 1] - un[j - 2])
+												/ (2 * pow(h, 3))) + unm[j];
+			}
+
+
+		}
+		unm=un;
+		un=unp;
+
+	}
+	FILE *fp= fopen("numplot2.csv", "w");
+	double x=sp->xmin;
+	for(int j=0;j<=jmax;j++){
+		x=x+h;
+		fprintf(fp, "%f\t%f\n",x,un[j]);
+		printf( "%f\t%f\n",x,un[j]);
+
+	}
+	fclose(fp);
+}
+
+
+int main(void) {
+soli_param sp;
+sp.N = 2;
+sp.h=0.1;
+sp.d=pow(sp.h,3)/3;
+sp.tmax=1;
+sp.tmin=0;
+sp.xmin=-30;
+sp.xmax=30;
+sp.jmax=(sp.xmax-sp.xmin)/sp.h;
+sp.nmax=(sp.tmax-sp.tmin)/sp.d;
+u0 = (double*) malloc(sp.jmax * sizeof(double));
+ustart(&sp);
+uj1 = (double*) malloc(sp.jmax * sizeof(double));
+ujeins(&sp);
+nextu(&sp);
+
+}